Furnace



F. E. GRUNWALDT FURNACE Filed 091.2, 192e s sheets-sheet 1 March 15., 1927.

March 15,1927. '1,621,066

F. E. GRuNwALD-r FURNACE Filed oct. 2. 1926 s sheets-sheet' 2 INVENTOR 6MM/ml?? Gela/ WM ATTORNEY Jl s v .5 d 1, .V R W n 2 m w W 6 S N O l, w n n n m m6. MA .muv o o 1 o o sv o 1 o o i s 3 o o o o z o o B .0 f 0 0 r M h 0 O T F D 6 A l o o QUn DN m o o U O 0 G F m Y :m.. h m n- O o. 4 E n O O O 0 O O D L F 1 F MN 7. 2 9 1 :w 1..

8 im 5 r. a M 2 Patented Mar. 15, 1927.'

FURNACE CO. INC., 0F TACOIVIA, WASHINGTON, A CORPORATION OF WASHINGTON.

FURNACE.

Application filed October 2, 1926. Serial No. 139,204.

My invention relates to improvements in furnaces and is in the nature of an improvement on the furnace disclosed in United 'States Letters Patent No. 1,440,071, issued Dec. 26, 1922.

rlhe general objects of ymy invention arel to improve and simplify the construction of furnaces of this nature and to render the same more reliable, efficient and economical in operation.

More specific objects of theinvention are,

same cheaper and easier to manufacture and` more efhcient in operation: To provide anv improved sectional fire pot and grate construction: To provide a furnace front of sheet steel rather than of cast metal construction: To provide novel air inlet means connected with the front door of the furnace and to provide novel arrangement of the water pan in the furnace front.

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawings. Y

' In the drawings Figure 1, is a perspective view of a furnace constructed in accordance with my invention showing parts broken away to reveal the interior.

Fig. 2, is a vertical sectional View of the same.

Fig. 3, isfa cross section substantially on broken line 3-3 of Fig. 2.

Fig. 4, is a detached view in elevation of the all steel furnace front,

Fig. 5, is a detached perspective of parts of the sectional fire pot and grate construction showing said parts separated a short distance to better illustrate their construction.

connected by an extensionportion 14 with and another smoke pipe 16 is connected'with i the lower portion of theV heating dome 12 at the rear.` Both" pipes l'and 16 are adapted to connect with the same vertical smoke lpipel. An air'inlet or draft damper 18 is provded'for the pipe 17 andl a pipe damper 20 of the usual form is provided in the pipe 16 and is connected ywith an operating rodV 21 that extends to the' frontof the furnace. ordinarily be closed except when the fire is being started or an unusually strong draft is desired'. I

The combustion compartment 11 'is larger than the ash receptaclel() and` larger than the heating'dome 12 thereby aording upper and lower shelf like portions 22 fand `23Are-Y spectively at the top and bottom ofl said-f combustion chamber' that proj ect-beyond the .limits of the ash receptacle and heating rlhis pipe damper 20 will dome and Vafford room for a plurality of vertically arranged steel heat tubes 24 that extend between the upper and lower shelves 22 and 23 a short distance inwardly from the walls of the combustion compartment and are open atboth ends. 'These tubes'v24 arel spacedapart a substantial distance at the forward end to permit-heated gases to This is an important feature be# cause it compels the major portionl of the'v circulate freely therebetween and the spacing y is lessened toward the rear 'the peripheries'` heated gases to pass outwardly between the tubes near the front of the combustion chambei' 11 and to travel in the narrow space between the outer sides of the tubes and-the wall of the combustion chamber 11 to reach t This insures that the the smoke f pipe 15.

heatedgases will not pass directly out ofthe-1 smoke pipe' 15 but will give up the greater portion of their heat through the tubes 24 and throughthe walls of the combustion compartment 11 before they reach the smoke pipe 15.

Two ofthe tubes 24 near the rear of the furnace extend downwardly alongside of the ash receptacle 10 as indicated at 19 and serveY as legs for the rea-i` of the furnace, air openings 29 are provided in the leg portions 19. The frorit'of thefurnace is supported by the bottom edge of the steel furnace front 13.

The steel front 13 of the furnace" is pro-y j videdwith an up'per opening 25 for awater pan 26,-almedialopening27 for double furnace doors 28 and 30 and a lower opening 31 for. an ash door 32. The edges of the steel front 13 arel bent as shown in Figs. 1,

v3 and 4V toafford suitableJ fianges 33 to which an` outerV drum 34, that extends entirely 'around'the furnace andprovides an air circulation space, is secured. The water pan 26 ispro-videdon the sides and bottom with a ange35 that is securely clamped by bolts between a' lframe piece 37 and the steel Y furnace front 13, thus aording an easily constructed, easily assembled and efficient way of supporting said water pan. Packing is preferably used between the furnace front 13 and the flange 35 soV as to form a seal and exclude smoke and dust and impure air. They location of the water pan above the combustion compartment and directly in front ofthe heating dome is of advantage in making for compactness of construction and giving the proper amount of.l evaporation. Y

Y Theupper coal door 28 is of substantially dish-shape and has a plate .38 on its inner side affording an air space 40. Tubes 41, preferably two in number, are supported by the yplate38, communicate with the air space 40. andextend into the combustion chamber 11^asshown tofurnish fresh air for hot blast i or combustion purposes to the upper portion coal.

offthe combustionv chamber.

The furnaceis substantially all of sheet steel-constructionand all joints are electrically Welded making them absolutely tight and .proof against the passage of dust or gas Y fronrthe gas `chamber to the clean air chambers Theash compartment and heating dmelare--o-f the same size and are disposedV in- ,alignment` relative to each other.

v'I-lhe'iire -pot of the furnace is of oblongv shapeand'is forme-dof a plurality of grate sections adapted to fit within the upper end ofthe lower ash compartment section of theV furnace and to'be supported on the lower shelf. portion 23.v This iire pot comprises end sections 42 andside sections 43 adapted tdinteriit and form the receptacle for the Both the end sections 42and the side sections 43-liave outwardly directed flanges at their top edge adaptedv to rest on the j lower shelf-like 1portion23 of the combustion chamber.

- The ends-of the sections43 are provided with notches 44 adapted to interit the ends offthe end sections-,42V andfhave studs l45 on the bottom adapted to set within notches 46 in the? bottoms 47 Vofthe lend sections.

The bottoms 47 of the end sections are provided with slotted draft openings v48. The side sections 42 have inwardly directed bottom iianges 50 provided with grooves 51 for the reception of pivotstuds 52 on the ends of grate bars 53 that extend crosswise of the fire pot. The grate bars 53 have downwardly extending arms 54 that arefpivotally connected with an operating link 55 lwhich extends outwardly through a slot 59 inthe front of the furnace and is pivotally connected with the top end of a shaker member 56. A shaker arm or lever 57 is adapted to be removably connected with the topend of the shaker member 56. The bottom end of shaker member 56 rests on a cam 58 and has a pivot 60 on the endthereof thatV extends down through said cam and'tlhrough a plate 61 aty the bottom of the furnace front.

The cam 58 has a foot piece 62 extending'.v outwardly therefrom by which it may be' turned to li t the member 56 and'release a notch63 on the shaker bar 55 from` engagement with the furnace front at the bot-tom of the slot 59, thus permitting the grate bars 53 to be oscillatedin shaking down the fire.

`When the cam 58 is replacedin the position" in which the outer end of the shaker bar' 55 is lowered the notch 63 will engage with its catch formed by the front of the furnace and lock the grate bars in their normal'hori- Zontal position.

The efficiency of this furnace isgreatly increased by the additional heating surface afforded by the tubes 24 and the heating'dome 12 on the top of said furnace. When the furnace is operating normally the damper 20 in the pipe 16 will usually Vbe closed thus preventing the' direct escape of heated gases" The heatedl from the heating dome 12. gases in the combustion chamber llmust' necessarily pass outwardly between' and around the tubes 24 before reaching the smoke pipe 15 thus insuring a maximum heating of the air that is circulating'throu'gh' said tubes.

The foregoing description and accomsof panying drawings clearly disclose al preferred embodimenty of my invention butV it will be understood that this disclosure is merelyl illustrative and that such changes in the device. may be resorted to as are within the scope and spirit' of the following the tubes further removed from said re box being spaced successively increasing dis tances apart.

3. In a furnace, avcombustion compartment, a smoke pipe connected therewith, a plurality of vertical tubes arranged around Vsaid combustion compartment and spaced inwardly from the wall thereof said tubes being close together adjacent the entrance to said smoke pipe to restrict the passage of heated gases therebetween and the tubes further removed from said smoke pipe being spaced further apart, and fire pot means in the bottom of said combustion compartment within the space surrounded by said tubes.

4. In a furnace, a vcombustion compar ment of oval shape having a fuel inlet openingat the front and having a smoke outlet opening at the rear, a plurality of vertical tubes arranged Vin continuous formation around said compartment and spaced inwardly from the wall thereof, the 'tubes being omitted from the space directlyy in front of said fuel inlet opening, the tubes extending from front to rear of said compartment being spaced apart gradually decreasing distances and the ltubes directly in the rear of said compartment being substantially in contact withA each other and a fire pot in the bottom of said combustion compartment within the space surrounded by said tubes.

5. In a furnace, a combustion compartment and a plurality of substantially vertical heating tubes arranged around said combustion compartment adjacent the wall thereof certainv of said tubes extending downwardly below the combustion compartment 'to form legs for the furnace.

bustion compartment of oval shape, a smaller 1 heating compartment disposed on the top of said combustion compartment and communi- 'f eating therewith, a smaller ash compartment disposed below said combustion compartment, a plurality of' heat tubes extending through said combustion compartment 0ut` side the limits of said heating compartment and said ash compartment said tubes being open at both ends, two of said tubes towards the rear of said furnace extending downwardly on the outside of said ash compart-V ment to form legs for supporting said furnac@I said leg tubes having openings intheir sides.

The foregoing specification signed a Tacoma, Washington, this 17th day ofv sept., 1926. Y

FRANK E. GRUNWALDT. 

